<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>border 三角形</title>
    <style>
        /* border设置的三角形的高 */
        /* border的底左边，由左边的border 高决定 */
        /* border的底右边，由右边的border 高决定 */
        .div1 {
            width: 0;
            height: 0;
            border-top: 120px solid black;
            border-bottom: 150px solid pink;
            border-left: 100px solid purple;
            border-right: 100px solid blue;
        }
    </style>
</head>
<body>
    <div class="div1"></div>
</body>
</html>